nptl/tst-_res1.c

   1 /* Copyright (C) 2003-2019 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Jakub Jelinek <jakub@redhat.com>, 2003.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 /* Test whether _res in glibc 2.1.x and earlier (before __res_state()
  20    was introduced) works.  Portable programs should never do the
  21    dirty things below.  */
  22
  23 #include <pthread.h>
  24 #include <resolv.h>
  25 #include <stdlib.h>
  26 #include <stdio.h>
  27
  28 void *tf (void *resp)
  29 {
  30   if (resp == &_res || resp == __res_state ())
  31     abort ();
  32   _res.retry = 24;
  33   return NULL;
  34 }
  35
  36 void do_test (struct __res_state *resp)
  37 {
  38   if (resp != &_res || resp != __res_state ())
  39     abort ();
  40   if (_res.retry != 12)
  41     abort ();
  42 }
  43
  44 int main (void)
  45 {
  46 #undef _res
  47   extern struct __res_state _res;
  48   pthread_t th;
  49
  50   _res.retry = 12;
  51   if (pthread_create (&th, NULL, tf, &_res) != 0)
  52     {
  53       puts ("create failed");
  54       exit (1);
  55     }
  56
  57   do_test (&_res);
  58
  59   if (pthread_join (th, NULL) != 0)
  60     {
  61       puts ("join failed");
  62       exit (1);
  63     }
  64
  65   do_test (&_res);
  66
  67   exit (0);
  68 }